From ec688b4723a041044226358bcd4dd6e2da39da49 Mon Sep 17 00:00:00 2001 From: Luca Muscariello Date: Thu, 23 Feb 2017 17:01:02 +0100 Subject: Initial commit: cframework. Longbow and Libparc Change-Id: I90378dbd30da6033b20fb1f829b3b822cf366c59 Signed-off-by: Luca Muscariello --- libparc/parc/algol/parc_RandomAccessFile.h | 426 +++++++++++++++++++++++++++++ 1 file changed, 426 insertions(+) create mode 100755 libparc/parc/algol/parc_RandomAccessFile.h (limited to 'libparc/parc/algol/parc_RandomAccessFile.h') diff --git a/libparc/parc/algol/parc_RandomAccessFile.h b/libparc/parc/algol/parc_RandomAccessFile.h new file mode 100755 index 00000000..f4f20150 --- /dev/null +++ b/libparc/parc/algol/parc_RandomAccessFile.h @@ -0,0 +1,426 @@ +/* + * Copyright (c) 2017 Cisco and/or its affiliates. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +/** + * @file parc_RandomAccessFile.h + * @ingroup inputoutput + * @brief A wrapper that provides random access to a file. + * + */ +#ifndef PARCLibrary_RandomAccessFile +#define PARCLibrary_RandomAccessFile +#include + +#include +#include +#include + +struct PARCRandomAccessFile; +typedef struct PARCRandomAccessFile PARCRandomAccessFile; + +typedef enum { + PARCRandomAccessFilePosition_Start, + PARCRandomAccessFilePosition_End, + PARCRandomAccessFilePosition_Current +} PARCRandomAccessFilePosition; + +/** + * Increase the number of references to a `PARCRandomAccessFile` instance. + * + * Note that new `PARCRandomAccessFile` is not created, + * only that the given `PARCRandomAccessFile` reference count is incremented. + * Discard the reference by invoking `parcRandomAccessFile_Release`. + * + * @param [in] instance A pointer to a valid PARCRandomAccessFile instance. + * + * @return The same value as @p instance. + * + * Example: + * @code + * { + * PARCRandomAccessFile *a = parcRandomAccessFile_Open(..); + * + * PARCRandomAccessFile *b = parcRandomAccessFile_Acquire(); + * + * parcRandomAccessFile_Release(&a); + * parcRandomAccessFile_Release(&b); + * } + * @endcode + */ +PARCRandomAccessFile *parcRandomAccessFile_Acquire(const PARCRandomAccessFile *instance); + +#ifdef PARCLibrary_DISABLE_VALIDATION +# define parcRandomAccessFile_OptionalAssertValid(_instance_) +#else +# define parcRandomAccessFile_OptionalAssertValid(_instance_) parcRandomAccessFile_AssertValid(_instance_) +#endif + +/** + * Assert that the given `PARCRandomAccessFile` instance is valid. + * + * @param [in] instance A pointer to a valid PARCRandomAccessFile instance. + * + * Example: + * @code + * { + * PARCRandomAccessFile *a = parcRandomAccessFile_Open(..); + * + * parcRandomAccessFile_AssertValid(a); + * + * printf("Instance is valid.\n"); + * + * parcRandomAccessFile_Release(&b); + * } + * @endcode + */ +void parcRandomAccessFile_AssertValid(const PARCRandomAccessFile *instance); + +/** + * Print a human readable representation of the given `PARCRandomAccessFile`. + * + * @param [in] instance A pointer to a valid PARCRandomAccessFile instance. + * @param [in] indentation The indentation level to use for printing. + * + * Example: + * @code + * { + * PARCRandomAccessFile *a = parcRandomAccessFile_Open(..); + * + * parcRandomAccessFile_Display(a, 0); + * + * parcRandomAccessFile_Release(&a); + * } + * @endcode + */ +void parcRandomAccessFile_Display(const PARCRandomAccessFile *instance, int indentation); + +/** + * Determine if two `PARCRandomAccessFile` instances are equal. + * + * The following equivalence relations on non-null `PARCRandomAccessFile` instances are maintained: * + * * It is reflexive: for any non-null reference value x, `parcRandomAccessFile_Equals(x, x)` must return true. + * + * * It is symmetric: for any non-null reference values x and y, `parcRandomAccessFile_Equals(x, y)` must return true if and only if + * `parcRandomAccessFile_Equals(y x)` returns true. + * + * * It is transitive: for any non-null reference values x, y, and z, if + * `parcRandomAccessFile_Equals(x, y)` returns true and + * `parcRandomAccessFile_Equals(y, z)` returns true, + * then `parcRandomAccessFile_Equals(x, z)` must return true. + * + * * It is consistent: for any non-null reference values x and y, multiple invocations of `parcRandomAccessFile_Equals(x, y)` + * consistently return true or consistently return false. + * + * * For any non-null reference value x, `parcRandomAccessFile_Equals(x, NULL)` must return false. + * + * @param [in] x A pointer to a valid PARCRandomAccessFile instance. + * @param [in] y A pointer to a valid PARCRandomAccessFile instance. + * + * @return true The instances x and y are equal. + * + * Example: + * @code + * { + * PARCRandomAccessFile *a = parcRandomAccessFile_Open(..); + * PARCRandomAccessFile *b = parcRandomAccessFile_Open(..); + * + * if (parcRandomAccessFile_Equals(a, b)) { + * printf("Instances are equal.\n"); + * } + * + * parcRandomAccessFile_Release(&a); + * parcRandomAccessFile_Release(&b); + * } + * @endcode + * @see parcRandomAccessFile_HashCode + */ +bool parcRandomAccessFile_Equals(const PARCRandomAccessFile *x, const PARCRandomAccessFile *y); + +/** + * Returns a hash code value for the given instance. + * + * The general contract of `HashCode` is: + * + * Whenever it is invoked on the same instance more than once during an execution of an application, + * the `HashCode` function must consistently return the same value, + * provided no information used in a corresponding comparisons on the instance is modified. + * + * This value need not remain consistent from one execution of an application to another execution of the same application. + * If two instances are equal according to the {@link parcRandomAccessFile_Equals} method, + * then calling the {@link parcRandomAccessFile_HashCode} method on each of the two instances must produce the same integer result. + * + * It is not required that if two instances are unequal according to the + * {@link parcRandomAccessFile_Equals} function, + * then calling the `parcRandomAccessFile_HashCode` + * method on each of the two objects must produce distinct integer results. + * + * @param [in] instance A pointer to a valid PARCRandomAccessFile instance. + * + * @return The hashcode for the given instance. + * + * Example: + * @code + * { + * PARCRandomAccessFile *a = parcRandomAccessFile_Open..(); + * + * PARCHashCode hashValue = parcRandomAccessFile_HashCode(buffer); + * parcRandomAccessFile_Release(&a); + * } + * @endcode + */ +PARCHashCode parcRandomAccessFile_HashCode(const PARCRandomAccessFile *instance); + +/** + * Determine if an instance of `PARCRandomAccessFile` is valid. + * + * Valid means the internal state of the type is consistent with its required current or future behaviour. + * This may include the validation of internal instances of types. + * + * @param [in] instance A pointer to a valid PARCRandomAccessFile instance. + * + * @return true The instance is valid. + * @return false The instance is not valid. + * + * Example: + * @code + * { + * PARCRandomAccessFile *a = parcRandomAccessFile_Open(..); + * + * if (parcRandomAccessFile_IsValid(a)) { + * printf("Instance is valid.\n"); + * } + * + * parcRandomAccessFile_Release(&a); + * } + * @endcode + * + */ +bool parcRandomAccessFile_IsValid(const PARCRandomAccessFile *instance); + +/** + * Open a new `PARCRandomAccessFile` instance. + * + * @param [in] file A `PARCFile` which refers to the file to open for random access. + * + * @retval `PARCRandomAccessFile` A new instance + * @retval NULL An error occurred. + * + * Example: + * @code + * { + * PARCFile *file = parcFile_Create("/tmp/file_chunker.tmp"); + * PARCRandomAccessFile *a = parcRandomAccessFile_Open(file); + * + * if (parcRandomAccessFile_IsValid(a)) { + * printf("Instance is valid.\n"); + * } + * + * parcRandomAccessFile_Release(&a); + * } + * @endcode + * + */ +PARCRandomAccessFile *parcRandomAccessFile_Open(PARCFile *file); + +/** + * Release a previously acquired reference to the given `PARCRandomAccessFile` instance, + * decrementing the reference count for the instance. + * + * The pointer to the instance is set to NULL as a side-effect of this function. + * + * If the invocation causes the last reference to the instance to be released, + * the instance is deallocated and the instance's implementation will perform + * additional cleanup and release other privately held references. + * + * @param [in,out] instancePtr A pointer to a pointer to the instance to release. + * + * Example: + * @code + * { + * PARCRandomAccessFile *a = parcRandomAccessFile_Open(..); + * + * parcRandomAccessFile_Release(&a); + * } + * @endcode + */ +void parcRandomAccessFile_Release(PARCRandomAccessFile **instancePtr); + +/** + * Create a `PARCJSON` instance (representation) of the given object. + * + * @param [in] instance A pointer to a valid PARCRandomAccessFile instance. + * + * @return NULL Memory could not be allocated to contain the `PARCJSON` instance. + * @return non-NULL An allocated C string that must be deallocated via parcMemory_Deallocate(). + * + * Example: + * @code + * { + * PARCRandomAccessFile *a = parcRandomAccessFile_Open(..); + * + * PARCJSON *json = parcRandomAccessFile_ToJSON(a); + * + * printf("JSON representation: %s\n", parcJSON_ToString(json)); + * parcJSON_Release(&json); + * + * parcRandomAccessFile_Release(&a); + * } + * @endcode + */ +PARCJSON *parcRandomAccessFile_ToJSON(const PARCRandomAccessFile *instance); + +/** + * Produce a null-terminated string representation of the specified `PARCRandomAccessFile`. + * + * The result must be freed by the caller via {@link parcMemory_Deallocate}. + * + * @param [in] instance A pointer to a valid PARCRandomAccessFile instance. + * + * @return NULL Cannot allocate memory. + * @return non-NULL A pointer to an allocated, null-terminated C string that must be deallocated via {@link parcMemory_Deallocate}. + * + * Example: + * @code + * { + * PARCRandomAccessFile *a = parcRandomAccessFile_Open(..); + * + * char *string = parcRandomAccessFile_ToString(a); + * + * parcRandomAccessFile_Release(&a); + * + * parcMemory_Deallocate(&string); + * } + * @endcode + * + * @see parcRandomAccessFile_Display + */ +char *parcRandomAccessFile_ToString(const PARCRandomAccessFile *instance); + +/** + * Close a `PARCRandomAccessFile` instance. + * + * @param [in] fileHandle A `PARCRandomAccessFile.` + * + * @retval true The file was closed successfully. + * @retval false An error occurred. + * + * Example: + * @code + * { + * PARCFile *file = parcFile_Create("/tmp/file_chunker.tmp"); + * PARCRandomAccessFile *handle = parcRandomAccessFile_Open(file); + * + * // use the handle + * + * parcRandomAccessFile_Close(handle); + * parcRandomAccessFile_Release(&handle); + * } + * @endcode + * + * @see parcRandomAccessFile_Open + */ +bool parcRandomAccessFile_Close(PARCRandomAccessFile *fileHandle); + +/** + * Read bytes into the provided `PARCBuffer` until the buffer limit is or the source EOF + * is reached. + * + * @param [in] fileHandle A `PARCRandomAccessFile` from which to read. + * @param [in,out] buffer A `PARCBuffer` into which data is read. + * + * @return The number of bytes read. + * + * Example: + * @code + * { + * PARCFile *file = parcFile_Create("/tmp/file_chunker.tmp"); + * PARCRandomAccessFile *handle = parcRandomAccessFile_Open(file); + * + * PARCBuffer *buffer = parcBuffer_Allocate(1024); + * size_t numBytes = parcRandomAccessFile_Read(handle, buffer); + * + * // use the data in `buffer` + * + * parcRandomAccessFile_Close(handle); + * parcRandomAccessFile_Release(&handle); + * } + * @endcode + * + * @see parcRandomAccessFile_Write + */ +size_t parcRandomAccessFile_Read(PARCRandomAccessFile *fileHandle, PARCBuffer *buffer); + +/** + * Write bytes from the provided `PARCBuffer` to the source file until the limit is reached. + * + * @param [in] fileHandle A `PARCRandomAccessFile` to which data is written. + * @param [in,out] buffer A `PARCBuffer` into which data is read. + * + * @return The number of bytes written. + * + * Example: + * @code + * { + * PARCFile *file = parcFile_Create("/tmp/file_chunker.tmp"); + * PARCRandomAccessFile *handle = parcRandomAccessFile_Open(file); + * + * PARCBuffer *buffer = parcBuffer_WrapCString("important data to go in the file"); + * size_t numBytes = parcRandomAccessFile_Write(handle, buffer); + * + * // continue writing to the file if needed + * + * parcRandomAccessFile_Close(handle); + * parcRandomAccessFile_Release(&handle); + * } + * @endcode + * + * @see parcRandomAccessFile_Read + */ +size_t parcRandomAccessFile_Write(PARCRandomAccessFile *fileHandle, PARCBuffer *buffer); + +/** + * Seek to the position in the file specified as an offset from the position. + * + * The position can be one of: + * PARCRandomAccessFilePosition_Start + * PARCRandomAccessFilePosition_End + * PARCRandomAccessFilePosition_Current + * + * @param [in] fileHandle A `PARCRandomAccessFile` to which data is written. + * @param [in] offset The number of bytes to offset from the provided position. + * @param [in] position The base posititon from which the offset is calculated. + * + * @return The number of bytes seeked. + * + * Example: + * @code + * { + * PARCFile *file = parcFile_Create("/tmp/file_chunker.tmp"); + * PARCRandomAccessFile *handle = parcRandomAccessFile_Open(file); + * + * size_t fileSize = parcFile_GetFileSize(file); + * parcRandomAccessFile_Seek(handle, -1, PARCRandomAccessFilePosition_End); + * + * // use the last byte of the file + * + * parcRandomAccessFile_Close(handle); + * parcRandomAccessFile_Release(&handle); + * } + * @endcode + * + * @see parcRandomAccessFile_Read + */ +size_t parcRandomAccessFile_Seek(PARCRandomAccessFile *fileHandle, long offset, PARCRandomAccessFilePosition position); +#endif -- cgit 1.2.3-korg